This report examines the potential of nature-based solutions to contribute to Scotland’s net-zero emissions target.

Scotland is facing the twin challenges of a climate emergency and biodiversity crisis. Changing the way we use the land and sea is now essential to both store carbon and help society adapt to climate change. Doing so can also help to improve the state of nature, which is experiencing unprecedented threats. 

Nature-based solutions feature prominently in the global biodiversity agenda. Vegetation growth and healthy soils, as well as sea floor integrity, provide a crucial way of locking away carbon emissions. However, it is the additional multiple benefits unique to nature-based solutions – addressing biodiversity loss, and adaptation to locked-in climate change – that makes them such a crucial part of a net-zero strategy. These are widely regarded as ‘no-regret’ actions to address climate change, but the evidence base to support their direct impact is complex. As such, further work is required to understand their practical application in Scottish circumstances.

This study assesses evidence for the greenhouse gas (GHG) mitigation potential of four nature-based solutions in Scotland (agroforestry, hedgerows, un-cultivated riparian buffer zones and the restoration of species-rich grasslands) and how these can help mitigate the impacts of climate change and reduce biodiversity loss. In addition, we provide a synthesis of the strength of evidence for including these as part of net-zero policy objectives and carbon codes.

Regional Land Use Partnerships (RLUPs) are being set up in Scotland to help achieve Scotland’s climate change targets through land use change and a natural capital approach. These partnerships facilitate engagement between local and national government, communities, landowners, land managers, and a range of other relevant stakeholders. Five RLUP pilots will produce a Regional Land Use Framework (RLUF) by 2023 using a natural capital approach which considers key natural assets and the benefits these provide to communities and the regional economy.

This project examines evidence from the UK and Europe for the use of the natural capital approach in successful partnerships, working across multiple sectors and landownership boundaries. It focuses on outcomes for climate change, biodiversity and benefits to local communities. It includes six case studies of partnerships which have incorporated elements of a natural capital approach.

Findings

Based on our analysis, a natural capital approach can help:

  • build a balanced overview of the range of ecosystem services and benefits to communities and stakeholders that land and natural assets can provide;
  • understanding of how different services may interact in response to projects and interventions, leading to multiple benefits or negative unintended consequences;
  • contextualise and respond to the different priorities and interests of specific partners and stakeholders, helping pre-empt and manage conflicts of interest;
  • act as a stimulus for local investment; and
  • bring stakeholders together to co-produce plans that can meet multiple objectives.

 

The Land Capability for Agriculture (LCA) classification for Scotland has been used since the 1980s to inform decision-making on land use management, planning and valuation.

This report explores the potential for a new research tool to estimate land capability under future climatic conditions – the Land Capability of Scotland research platform. Development in this project has been based on the original LCA guidelines. The platform is a set of computing tools (not PC based) for data integration, calculation, analysis, mapping and visualisation, allowing models to be run to estimate land capability constraints and generate digital maps.

The Land Capability research platform is designed to be a ‘risk and opportunities assessment’ tool operated by researchers; the Land Capability of Scotland research platform does not replace the existing published LCA classifications.

The platform has initially been developed to produce estimates of Land Capability for Agriculture under different climate change projections and has further potential to support research on a broad range of land uses and benefits, such as forestry and ecosystem services.

Results
  • The original LCA guide has been successfully coded and computing structures implemented, integrating multiple spatial data sets and modelling tools to estimate the individual constraints that determine the LCA and its overall classification.
  • A key challenge is the ability to model soil water balance appropriately. A soil water balance model was implemented within the platform, but further work is required to better calibrate the model and validate the estimates. 
  • Initial analysis between two baseline periods indicates that climate change has already altered land capability and is likely to further impact it in both positive and negative ways in the future. 
  • Reduced water availability is likely to be a key determining factor. Initial analysis suggests that soils, especially those with a low water holding capacity, are likely to become drier and with greater frequency. 
  • This implies an increased risk of crops, grassland and vegetation experiencing difficulties in accessing water. The LCA and constraint maps indicate where this may occur.
  • There is a substantial risk that land currently classed as prime agricultural land (classes 1 – 3.1) may experience reduced production capability due to dry soils in an increasing number of years with drought conditions.
  • Conversely, potentially areas such as the north-west Highlands may experience increased precipitation totals in some years, meaning soils there becoming wetter.
  • There is likely to be increased annual variability in land capability associated with increasing climatic variability and extreme events, such as wet seasons or years followed by dry ones.
  • The platform development has been a ‘learning by doing’ iterative process, and further improvements are possible. The research platform will continue to be used and developed in the Scottish Government’s 2022-2027 Strategic Research Programme.

The Scottish Government has set ambitious targets for reducing greenhouse gas (GHG) emissions from Scottish agriculture; in 2018 these emissions represented 16% of the nation’s total. As part of a commitment to reach net-zero emissions by 2045, the Climate Change Plan update requires the equivalent of a 31% reduction in agricultural emissions by 2032 from 2018 levels. However, between 1990 and 2019 Scottish agriculture’s emissions decreased by only 13%.

This report explores how data on emissions and nitrogen from the Scottish Farm Business Survey, using Agrecalc, can be used to help design policies aimed at reducing emissions in a sustainable way. Agrecalc is a farm carbon calculator developed by SRUC and used widely within Scotland.

Findings and recommendations

  • For dairy farms a linear relationship was found between production and GHG emissions intensity– in other words, as milk production per ha increases, GHG emissions per ha increase. Other farm types showed no clear linear trends between production and emissions. 
  • Emissions intensity varied both between and within farm types. Variation between farm types largely reflects differences in enterprise mix. For example, ruminant livestock enterprises are intrinsically more intense emitters than arable enterprises.
  • Variation within a given farm type can also reflect how enterprises are managed; for example, through adoption of innovations and best practice. The results show some evidence for this, although the patterns are neither linear nor consistent.
  • We find little evidence of a clear relationship between lower emissions and stronger economic performance. Nor do we find clear evidence for the effects of managerial efficiency. 
  • We found that Nitrogen Use Efficiency (NUE) is a potentially useful agri-environmental metric, as this provides a proxy for farm level efficiency of nutrient use. However, the NUE values calculated from the current SFBS dataset omit important input information, such as legumes. Therefore, its value should be further assessed and measured before potential use as a farm performance metric.
  • We found farms with similar structural characteristics have different emissions intensities. Collection of additional SFBS data items could improve subsequent analysis. 
  • Although the focus has been on gross emissions, the approach could usefully be extended to consider net emissions, in particular, sequestration into farm soils and woodland. This may, however, need to await further refinements to Agrecalc and collection of additional SFBS variables, such as hedgerow quality.

Sustainable management and protection of soils is a priority for Scotland. Soils are a valuable but vulnerable natural asset and underpin environmental, economic, and social functions. The importance of soils is mirrored in the wide range of regulations, policy and guidance that have evolved over time.

This report updates the previous ClimateXChange Soil Governance in Scotland report (McKee 2018) to reflect changes in policy and legislation for the conservation and management of soil in Scotland, with extensions to consider soil carbon and biodiversity.

Key findings

  • Since 2018, 29 soil related policies have been updated or introduced across a range of legislative areas, including: agriculture; climate change; forestry; planning; diseases and pest control; plant health and genetically modified organisms.
  • Soil biodiversity is included in legislation either as a part of biodiversity as a whole or as a part of soil health.
  • Soil carbon is explicitly considered in relation to peat, most predominantly in Scotland’s National Peatland Plan. Soil carbon may also be considered within general climate change legislation, although is not explicitly mentioned.
  • There is no single policy for soil conservation and management.
  • No updates to policy regarding policy effectiveness have been made since the 2018 report, resulting in a continued a gap in soil monitoring for policy effectiveness.
  • Specific gaps can be identified in relation to
    • the role of protection and restoration of peat in climate change mitigation legislation, building on current inclusion in land use plans and legislation, and the Climate Change Plan;
    • the recognition of soil biodiversity as a part of biodiversity legislation; and
    • the explicit inclusion of wider soil carbon into land management and agricultural legislation.

Agroecology is receiving increasing attention for its potential to reconcile environmental, sustainability and food production goals, through restoring the health of agricultural ecosystems and increasing the resilience of farms to future challenges.

This study examines five different agroecological approaches that are currently practised in Scotland to determine their potential to support the delivery of policy targets relating to climate change, biodiversity, and food production. The approaches are: agroforestry, low-input systems, organic, integrated farm management (IFM) and regenerative agriculture.

Findings

  • The five models investigated showed considerable overlap in the farming practices typically adopted and there was no fixed boundary between these models. The models were also not mutually exclusive (e.g. an organic farm may also practise agroforestry).
  • Regenerative agriculture, integrated farm management (IFM) and organic farming had the widest range of practices considered as ‘core’ reflecting their broad scope and ‘toolbox’ approach to select practices appropriate to specific locations and circumstances.
  • Agroecological approaches are strongly knowledge focused with the farmer as the central decision-maker. A prescriptive set of practices for each model, therefore, goes against the grain. Farming system, geographical location, resource availability, constraints, mindset and priorities of the farmer, all influence the practices adopted under any specific agroecological model.
  • A farm-scale shift towards an agroecological model requires expertise, commitment and, in some instances, significant investment. With a typical delay before agronomic benefits are realised, farms need the financial capacity to buffer the economic costs of transitioning.
  • Labelling or certification to increase the market value of agroecological produce may incentivise farmers to adopt agroecological approaches. However, ensuring consumer demand and willingness to pay presents a challenge. 
  • Outcome-based approaches, whether for certification or agri-environment purposes, require robust, user-friendly metrics, to enable farmers to monitor and benchmark performance and adapt management to optimise outcomes.
  • The five agroecological models have the potential to reduce adverse environmental impacts associated with intensive agricultural production at the farm level.
  • While agroforestry and IFM were perceived to match yields attained in conventional systems, organic, regenerative agriculture and low-input systems were perceived to be lower yielding. However, all models were perceived to increase farm resilience and stabilise yields either slightly (low input and organic) or intermediately (agroforestry, regenerative, IFM).
  • The potential of agroecological approaches to deliver environmental outcomes depends on efficiently using land and external inputs. 
  • Identifying synergies and trade-offs is vital to help us design agroecological systems that optimise economic, food security and indeed social outcomes. There is a lack of system-based research that concurrently explores evidence for a diversity of outcomes in the Scottish context.

 

Monitoring soil health in a changing climate is a priority for the Scottish Government.

In 2020, CXC published a baseline report that pulled together existing research on the vulnerability of Scottish soils to climate change. The report found that, while Scotland has a significant knowledge base on soils, there was no single indicator that could be applied to all soils, climatic conditions or land uses.

This scoping study takes the 13 potential indicators the baseline report identified and considers their strategic relevance to monitoring soil health in the context of existing land use Scotland. 

Key points

  • Potential primary soil health indicators were identified for several land use categories.
  • However, it is not possible to identify a single, definitive indicator for each individual land use category and suitable indicators were not identified for several categories such as Urban or Amenity soils.
  • Seven indicators were considered extremely important for more than 50% of the categories assessed:
       o soil organic matter content
       o topsoil depth
       o erosion features
       o bulk density
       o bacteria and archaeal diversity (DNA methods)
       o fungal and nematode diversity (DNA methods)
  • Visual assessment of soils, moisture content and dissolved organic matter were considered extremely important for the fewest categories, though moisture content was considered the primary indicator for transport infrastructure.

The issue of dependency between indicators generates a layer of complexity that requires further exploration.

“Thank you very much – this is exactly what we needed.”

RESAS commissioning officer

  • ClimateXChange’s extensive work on peatland restoration demonstrates our ability to manage a wide-ranging, multi-year programme of research with diverse stakeholders – from farmers and landowners to government bodies such as NatureScot and Scottish Water.
  • Our research has helped ensure peatland restoration – a strategic priority which has received substantial government funding – is well designed, correctly targeted and achieves results on the ground.
  • Since 2017, we have published eight substantial pieces of research on peatlands (on top of extensive work in the related field of soil). We have evaluated previous restoration initiatives; provided advice on how practices might be improved; and examined cost-effectiveness and economic impacts.

Why peatlands matter

Scotland is a global pioneer of peatland restoration, an important element of addressing the climate emergency in Scotland and beyond. Peatlands cover nearly a quarter of Scotland and contain over half of Scottish soil carbon. However, a high proportion is degraded, causing substantial greenhouse gas emissions. To mitigate this and boost carbon storage levels, the Scottish Government has made substantial commitments: in 2020 it pledged £250m to help restore 250,000 hectares of peatland by 2030. This builds on the Peatland ACTION programme, launched in 2012 and administered by NatureScot (formerly Scottish Natural Heritage – SNH)

What we did

  • Built strong relationships with key policy officials in the Scottish Government and SNH/NatureScot.
  • Facilitated a research priorities workshop for stakeholders to design robust research that would explore available data (through Peatland Action and other sources) and report the findings in plain English.
  • Contributed understanding of the broader issues, to help officials refine and define the questions that could usefully be asked – and answered – to inform practical action and delivery.
  • Helped access extensive knowledge and expertise in a complex scientific area while simultaneously helping researchers understand the policy context and the perspective of the officials charged with delivering to very tight timescales.
  • As the project portfolio progressed, recognised the breadth of interest in this area, encouraging input from all stakeholders at an early stage. This led to a stronger cross-sectoral approach and delivered clearer outputs.
  • Explored the potential for emissions savings from re-wetting peatland currently used for agriculture in Scotland.
  • Delivered substantial portfolio of research, including on: peatland drainage; the impact of muirburn; potential emissions savings from restoration; wider use of Peatland ACTION data; cost-effectiveness of restoration; use of peat for horticulture; physical limitations to restoration; and stakeholder experiences of restoration work.

“The CXC project on the emissions saving potential on agricultural land is directly helping to shape the Scottish Government’s policy and analytical thinking on where to target and prioritise peatland restoration in the future.”

Scottish Government policy team member

Evidence for restoration spend

Our work helped to meet challenging targets in a priority area by understanding what works and where practice might be improved: clear, well-directed and wide-ranging research has directly informed strategic development of Peatland ACTION and practice on the ground. Our extensive portfolio of work has given us the knowledge and oversight to brief the Scottish Government’s expanded team, helping new members get up to speed quickly and set research priorities. Our track record on peatlands means we can immediately support delivery of the commitments in the Climate Change Plan Update (CCPu) and help government agencies target significant restoration spend effectively.

Heat pumps are an efficient way of producing heat from electricity; they operate by capturing the latent heat in the air, ground or water and using it for heating.

Heat pumps are expected to play a significant role in decarbonising heat in Scotland; the Climate Change Committee has described them as a ‘low-regrets’ option, and they feature prominently in Scotland’s Draft Heat in Buildings Strategy.

However, heat pump efficiency can vary across the heating season and in different buildings, meaning the costs and impacts on wider energy systems depend on the context.

This desk-based review looks at evidence on how heat pumps currently, or are likely to, perform in practice in Scottish buildings. The research identifies best practice relevant to Scotland and gaps in the available evidence.

The scope of the research was for both domestic and non-domestic buildings. However, the majority of the relevant datasets relate to domestic settings.

Key findings
  • Poor heat pump performance is most likely to arise due to poor design and specification. This means appropriate design and installation are the most important considerations to ensuring heat pumps perform well in Scotland.
  • Heat pumps are a mature heating technology used in several European countries, including countries with colder winters than Scotland. The review found no evidence to suggest that heat pumps could not operate effectively or efficiently in Scotland. 
  • The review suggests there is occupant satisfaction with heat pumps.
  • There is evidence that heat pump performance could be maximised by building confidence in heat pump technology among consumers and the supply chain. 
  • Where running costs were monitored, heat pumps were cheaper to run than previous electric, oil or LPG heating systems and are a key outcome for occupant satisfaction.